Percussion firing mechanism



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OWEN DAVID LUCAS, or wES'rIvIINs'rnn, LONDON, ENGLAND, ASsIeNoR rro vICKERs p LIMITED, or wnsfrMINsrnR, LONDON, ENGLAND, A BRITISH COMPANY.

PERCUSSION FIRINGl MncIIANIsr/r.

Application led October 11,1926, Serial No. 140,701, and in GreatrBrtain October 22, 1925.

This invention relates to percussion tiring mechanism of the kind having a spring actuated striker or tiringv pin which, after being retracted and released, is forced by its spring into contact with a percussion cap or primer to effect detonation. The im# provided applicable to flare, smoke or `signal bombs which are'dropped from air craft and in which the lfiring mechanism is operated by the act of dropping the bomb.

According to the present invention Vthe spring of the striker orliring pin is normally in an unstressed condition and the striker is retracted against the action of this spring by an axially movable member having spring hooks, claws, or the like which engage with part of the striker and are held in engagement therewith by contact with the inner surface of a sleeve wherein the striker' and the said member are disposed but which, when the striker has been retracted to a predetermined extent, come opposite a recess in the sleeve so that they are free to move aside to release the striker which is then impelled byV its spring on to the percussion cap or primer; the blow given by the striker is Vthus constant irrespective of the speed or force with which the striker is retracted since the point of release of the striker is determined only by the amount of retraction necessary to bring the spring'hooks or claws opposite the recess in the sleeve. Y

The aforesaid, axially `movable member may comprise a tube which is formed with a number of longitudinal slits or saw-cuts -to provide spring fingers whose ends are bent inwards to constitute the aforesaid spring hooks or claws and this tube may be filled with a metal plug through which and through the tube and also through the Sleeve, a shearing wire or pin passes. The ends of the hooks or claws may be rounded somewhat and may bear I againsta slightly rounded shoulder formed by a circumferential groove at the end of the striker stem, so that t-he spring of the striker assists in moving the said hooks or claws aside to release the striker aS aforesaid. A guide pin may pass transversely through the-tube and through the plug and Aits outer ends may engage in longitudinal slots or recesses in the outer end of the sleeve, this arrangement facilitating the assembly of the shearing wire or pin and also firing mechanism isA particularly preventing liability of the latter becoming shearedby forcible turning vof the'tube about its axis. I A

f In order that the'said invention may be' clearly understood andreadily carried into effect, the same vwill now be described more fully with reference to the accompanying drawings, in which:-

Figure l is an axial section showing theY fuze of a smoke or signal bomb for aircraft, f

this fir/:c having `firing mechanism constructed in accordance with thisinvention. Figure 2 is an enlarged View of the upper part of Figure l, and

Figure 3 is a side elevation of Figure 2.

A is the striker head, A1 is the striker l stem and A2v is the striker spring interposed between the head A1 and thersleeve creasing A3 which is screwed on to the fuze body and in which the striker is arranged, this spring being normally in the unstressedfcon- Y dition. vB is the aforesaid tube which lis slidably mounted in the upper or outer end of the sleeve A3 and is formed with a number of longitudinal slits toV provide spring lingers Bl having hooked ends b Vwhich normally engage beneath a shoulder a formed by a circumferential groove on the outer end of the striker stem, the hooked ends and the shoulder being slightly rounded as shown in Figure V2. The tube B is filled with a metal plug Bzand a shearing pin or wire b1 passes through the tube, the plug and the sleeve A3. A guide pin b2 also passes through the tube B.. and the plug B2 and its` projecting ends engage in slots or recesses as, as in the outer end of the sleeve A3 so as to facilitate the assembly of the shearing pin or wire b1 and prevent the latter from being sheared by angular movement of the tube about its axis. end of the sleeve A3 is formed with an in-V ternal annular recess A4 to receive the hooked ends b of the spring ingersB1 when they come opposite vthe said recess. A safety pin C passing through the sleeve A3 and a circumferential recess'in the striker head A,

The outer v normally prevents movement of the striker Vby its spring A2 spring fingers B1 opposite the annular recess A4 in the sleeve A3. The spring fingers then move laterally out of engagement .With 1 the shoulder a, thev rounded formationof this'shoulder and of the hookedends of the spring iingersr enabling theV spring A2 to as-V Y (which is` what is illustrated in the accompanying drawings) vthe' plug B2 is lattached Y to part of the aircraft by a lanyard or link l Letters so that when the bomb is dropped its Weight aiiects the retraction of the striker and its release as aforesaid.

`What 1I Vclaim andv desire to secure by Patent of the United, States is -1. Percussion firing mechanism` comprising in combination a striker or iiring pin, a percussionl cap, a spring. for Ymoving said Y strikervr to explode saidy percussion cap, said spring being normally in an Yunstressed con-,

dition, an axially movableV tube 'formed with a number of longitudinal slits to'provide spring fingers, inwardly bent portions of said spring lingers Vconstituting hooks, a rounded projection on the strikerwith which said hooks engage, a sleeve against the inner surface. o'fwhich said spring fingers bear to 'hold the hooks in en agement Vwith the `rounded projection on t e striker, and a recess in said sleeve into Which sald spring iin- VcomeY disengaged from Vthe said rounded projection and the striker is then impelled on Vto the percussion Vcap by this spring.

2. In percussion firing ,n mechanism, the

combination With the elementsV claimed in claim l, of a metal plug Which lills the tube,

anda shearing. Wire passing through theV plug and the sleeve surroundtube, the metal ing the spring ingers.

In percussion firingY mechanism, thev combination with the elements claimed in claim l, of a metal plug which iills the tube, a shearing Wire passing through the tube, the metal plug and thesleeve surrounding the spring fingers, a guide pin which passes through the tube and through said plug and the outer ends of Which engage in longitudinal recesses in lthe outer end of said sleeve..

4. In percussion firing mechanism for use with a smoke or signal bomb to be dropped `from aircraft, the combination With the elements claimed in claim l, of meansrat the outer end of the axially movable tubeV for attaching'to part of the'aircraft by a fiexible connecting device so that When the bomb.

is dropped its Weight effects the retraction Y of the striker.

OWEN, DAVID LUCAS.

Ygers move at a certain point inthe travel of i the axial movable tube so that the hooks be- Y 

